Wednesday, January 26, 2005
Tuesday, January 18, 2005
General Circular – January 2005
TO: Special Interest Groups of the SAMAA
This is a general communication to the Special Interest Groups. Some matters are for information; others need your action.
Team selection parameters and processes
This is another reminder for those competitive SIGs that have international participation. You must table their team selection parameters to the SAMAA management committee for ratification, after which it must be published. Please make sure that you submit this information PRIOR to the start of the process. It can’t do any harm to submit it again, if you are already in the selection process.
Peter Joffe is doing a great job on the SAMAA News, and he will routinely include news of the SIGs activity, provided of course he is supplied with information. Please make use of this opportunity to advertise your activities.
Entry forms for the Nats events that are scheduled for the early part of the year have been included in the next issue, but some would have missed the deadline. Please use your electronic means, or web pages to communicate this information. Get in touch with John Godwin if you want to use the SAMAA website as a vehicle.
Radio control frequencies
There is an Excel spreadsheet with this message that details the current state of frequencies available to us. If you are aware of anyone using illegal equipment, please let me know so that we can take the necessary steps to protect our interests. By the same token, if you are aware of radio control activity from an unregistered site, report this too.
SIG operation revisited
Despite the circular of 11th November 2004, the SAMAA office has received no minutes of past meetings from some of the SIGs. If there is to be complete transparency, it is imperative that you fulfil this minimum requirement. This can be e-mailed, faxed, or posted, entirely up to you. (A written monthly report to the SAMAA management committee, mentioning recent activities per region, proposed activities, development and transformation initiatives, minutes of your meetings, etc).
Monday, January 17, 2005
I started off by drilling out the standard 2.3mm pinion to3mm, and used a shaft from a CD-ROM motor in order to be able to set the spacing between the motor and the pinion at 5.5mm.
As the motor pinion is placed between the main gear and the tail drive gear, there is not much room for changing the number of teeth on the pinion. As the pinion is also longer than normal, chances of sourcing alternative pinions are also very slim.
Another option would be to use two GWS pinions on the same shaft, but I tried this before I realized that the distance between the motor and the pinion is important.
Needless to say, my pinions were installed too close to the motor and I did not have any more 2mm pinions.
As I was on leave and had some spare time available, I took up the challenge to optimize the windings to suit the standard pinion which would also make it possible for others to replicate my results.
In order to get some indication of the performance of the motor I placed a 50mm wide and 250mm long ply plank on the skids, and weighted it down on my workbench. I set up the throttle curve to give about 85% throttle at zero pitch, and full throttle at full pitch (7 degrees as recommended).
My aim was to obtain about 70W from the VL motor at full pitch and full throttle, with a head speed of about 2000RPM.
My experience is that the standard Speed 400 motor gives about 80W on a fresh battery pack, and then drops to about 60W as the motor starts heating up. As can be seen from the results below the current draw on 9winds was way too low, so I tried 7 winds.
Satisfied with the results of the bench tests, it was off to the local cricket field for flying tests.
Performance was much better than on the standard brushed motor, as there was no power sag after flying for a minute or two), and aerobatics was possible using a 3 cell Kokam 1500 battery.
Flying time was more than adequate -after flying for more than 15 minutes it took less than 1100mAh to fully recharge the battery.
As I was aiming for about 10-15 minute flying time and it seemed that the current draw in the air was significantly lower than the static draw, it seemed that it would be worthwhile to rewind the motor with 6 winds.
This proved to be the ideal setup, with more than adequate power for full 3D aerobatics, and the motor only slightly warm.
Unfortunately we did not set the timer on the radio, but flying time was in excess of 10 minutes!
Winds Pitch Volts Amps Watts Blade RPM
9 0 11.6 2.4 27.8 1740
9 +7 11.3 3.6 40.7 1590
7 0 11.5 3.1 35.7 2250
7 +7 10.7 5.6 59.9 2070
6 0 10.6 6.0 66.8 2130
6 +7 9.3 10.4 96.7 1740
Saturday, January 15, 2005
Although traditionally the South African Aerobatic Masters event, is a qualifying procedure during the course of the year to be eligible for an invitation to the event, the MAASA Committee decided that this years event, to be an open event. Reasoning behind this is generally to increase the level of activity countrywide, to promote aerobatics and to show all prospective pilots out there what a competition is all about. This decision was welcomed by all, and we had 25 entries. MAASA also provided 10 judges, 3 from far-away areas that were flown up to Johannesburg.
Getting back to the competition, we had once again seen quality flying from sportsman class to the FBA class. This was also to be the last leg of team selection for the FBA class, to participate in the World Champ’s in France in 2005. Normally 3 team qualifying event are flown, starting from the previous years masters competition, followed by a Nationals and then finally, the 3rd leg, a Masters event.
The team is then chosen from, placings and the best 2 out of 3 results to count. The 2005 FBA Team will consist of experienced international pilots, names are Pierre Marais, Danie Potgieter and Andre Stockwell, with reserve pilot, Savas Nicolaides. Team manager for France is Burt Botha and the team will now commence preparation for the worlds regular training session will be conducted with all 4 team members, leading up to departure around August 2005.
We had participants from all over, with a huge entry from Bloemfontein. Things seem to be happening up there, and there is a rumor that the NATS 2005 will be held in Bloemfontein. This will be welcomed by MAASA, as it will be a very central venue for the whole country. Once again the weather played havoc, Saturday morning with very strong winds and the start was delayed, hoping that the wind would subside a bit, to no avail. The CD, Danie P (SNR) and chief Judge, Ivan Olivier, got the show going with about a 2-hour delay. This posed no problem as we were all eager to fly, and the “Ready Boxes” were controlled very well, with no delays.
Aerobatics seems to be very strong at the moment, judging by the level of flying, that I witnessed over the 2 days. I also spoke to most of the pilots, and there appears to be a lot of interest and eagerness for the future, and this is most welcoming news MAASA, once again pleads with all those past and prospective aerobatic pilots, to come and fly, and enjoy the passion around aerobatics. They say once you can master aerobatics you could fly anything. MAASA’s ability to promote aerobatics is jointly possible with all the members, as MAASA needs guidance from its members. I have received calls from Rustenburg, Piet Retief, inquiring about how to get into aerobatics, this is obviously promising.
After 2 rounds on Saturday, MAASA hosted a braai, and this was welcomed by all to pilots. The talk was about the days flying and what to do different the next day with 2 flight lines provided by Ivan, Sunday got off to a great start with good weather.
Once again all pilots must be complemented by their flying skills, and we saw some new FBA pilots in the making. See all attached results.
By the time you read this, 2005 will be fresh, so it is the right time to start practicing. Give MAASA a call for any queries, and I hope to see many new members, active in 2005.
Wednesday, January 12, 2005
· Murphy’s Laws of Aeromodeling
· Correlated By ………Claude MacKrill
Please add some of your experiences to the list & mail them back to me PLEASE!!!!!!!!!!!!!!!!!!!!!!.
Murphy’s Law If Murphy’s Law can go wrong it will
Murphy is out there waiting for you……
Murphy’s Law on learning to start engines, “You Bleed You learn”
Murphy’s Law. If your battery can fall out it will, (ask Pierre.M about the Nats in CapeTown)
The 50-50-90 rule Anytime you have a 50-50 chance of getting something right, there's a 90% probability you'll get it wrong.
If you do a great landing
The runways moved
Your undercarriage collapses
If there is an immovable object near, that is where you will land.
Only on perfect flying days will u forget your TX at home
If you use a wing joiner, you would have left it at home the week after you left your TX at home
If you can't go flying tomorrow, the weather will be perfect.
Your glow plug will blow just as you are about to start for a competition
If you let your future wife choose the honeymoon hotel, there won’t be a flying field close.
Your worst landing is always done at a pattern comp
If your retracts fail it will do so on a tar runway
If you have to walk 100m to the take off area (F1 Field Pretoria)
Your engine wont run
You forget your starter battery
The temp is 40 deg in the shade
You forgot the calling sheet.
A call of nature becomes Very Very Urgent.
You forgot the Coffee
Its to dark by the time you get there
If you need a new prop you will have one either side of the size you need
If your tank leaks, the size of the leak is inversely proportional to how difficult it is to get to the tank
When your wife cleans up after you messed up the lounge, the pieces of balsa she throws away are the parts you need
Corollary The parts she lovingly saved for you is the scrap. (PS don’t tell her otherwise the next time the wings will go out with the good parts)
If you cut your finger while starting all the plasters in your box will have “Goofy” printed on it.
When your throttle linkage fails you will still have a full tank, as it never fails on an empty tank (ask Damion (PRF)……20min @ 150 km.ph)
The expensive kit you just bought, is on sale for half price at the other dealer.
Murphy’s law of fuel
The fuel mix you have to use is always the most expensive.
If your engine seized it was the “other” blend you should have run
Murphy’s law of Glo Plugs
The plug you just threw in the bush was “OK” the glo battery was flat.
The new plug in your box is not the one you need for your engine.
A new glow plug will last forever if you have spares, but only about a half-an-hour is you don't.
Murphy’s law of Engines
You will always purchases the “New model” a week before the “New New” model goes on sale.
The engine on sale is always one size to small, or to big for the model you just built.
After hours of setting, changing pipe lengths, New fuel mixes, and Volumes of “Colourful adjectives” you bring the settings back to where they were in the first place, everything works
The probability of an engine quitting is directly proportional to the distance the airplane is from the landing area
Murphy’s law of “take off’s”
The only molehill on the runway will get in your way….Splat
An engine that ran perfectly for months will splutter & die as you lift off. (At a comp)
Murphy’s law of Landings
If you missed the molehill on take-off it will get you on landing ….Splat
If it's not a tail dragger, it will be.
Murphy’s law Transmitters
The one function your computer radio does not have is the one you desperately need
Murphy’s law of Weather
On flying days the wind will blow
On Non flying days, no wind
· On Public holidays the wind blows
On public holidays you promised to take the wife out, No wind
On perfect days, the mist refuses to lift.
On perfect public holidays, the mist is situated ONLY over the flying field
The wind is never blows at the “other field” until you decide to go fly there
It never rains at the flying field unless it’s a flying day.
Murphy’s law of Frequency
If a beginner joins the club it will be on your Spot
If there are 5 flyers at the field, 3 will be on the same spot
When visiting another flying club yours is the spot they have the most interference on, they don’t tell you until you “Splattered”, they then say “what did I tell you the interference is still there”. And then warn you about that spot.
Nothing is easy as it looks.
When things go wrong, that cannot possibly to go wrong, it’s usually impossible to repair.
Murphy’s law of Covering
The right way to cover a certain shape is always found out the day after you just covered it the wrong way.
Monday, January 10, 2005
Although the weather at times was trying to disturb the event, we still had a great turn up of Pilots, and some wonderfull flying. The interesting part of this event was that some Full scale enthusiasts came form as far as Mpumalanga in their planes to enjoy our great hobby, and have some fun. In fact, we even received e-mails from foreign countries of people showing interest in such idea as flying at the southern most tip of Africa! So we are looking forward to this event becoming a huge success in the future.
Our motto was that we would not allow more than three pilots flying at the same time, as this distracts onlookers and pilots alike, because if you cannot hear your plane, flying it becomes difficult. Also, we arranged for model car enthusiasts to participate by allocating a time slot for them at the Airfield. This added some more flavour to the event. We had a Bell Jet Ranger and Cessna 172 taking people for short "flips" and then of course the awesome display of Finley Smith in his Yak 52. He even took some of us up to experience up to 6.5+ G's. Something I personally will never forget.
The R10 000.00 in cash prizes were handed out on the final day, and we decided to hand over our Tip of Africa floating trophy to Finley Smith for 2004.
All entrance fees received at the gates, about R6000.00, was handed over to local charity.
We are already brainstorming this years event, and will soon notify everyone on dates, program etc.
Saturday, January 08, 2005
The second day was for flying 2 back-to-back rounds of the 'unknown' schedule, contributing 40%, and a single 4 minute free-style round adding the final 10% to the score.
The free-style was also run as a separate competition for which there was a separate trophy. Some pilots opted not to fly the free-style.
Our Judges for the event were Ivan Olivier, Rob Hearn and Hermann Schreuder.
Saturday morning saw all pilots at RMAC very early with some putting in a quick flight before the pilot's briefing which started at 7:45.
Flying started 'on time' at 8:00 with a sighter flight for the judges and everything went perfectly according to the timing plan thereafter.
To keep things fair each round had a new starter, with 9 entries and 6rounds to fly meant that everyone had a turn to be either first or second up and also to end a round.
After the first round scores were very close and after the all the known rounds were flown, in rather strong blustery weather, 5% covered the top 5scores.
Unfortunately Ruan Lourens had a throttle linkage problem in the first round which put him out for the rest of the competition, apart from that there were no other incidents. The unseen schedule, which was handed out at the pilot's briefing, came into play with many pilots scratching their heads trying to work out what was required.
Sunday morning got off to a prompt start with much better weather conditions. The unseen schedule was fairly challenging with some pilots scoring better than in the known rounds.
Following the unknowns was the 4 minute free-style event which produced some very interesting and well put together flying, what with torque rolls, hovers, waterfalls , high alpha flight and many other manoeuvres, and some to music, which do not form part of the disciplined category was most entertaining and a pleasant end to a great weekend's competitive flying.
The results were as follows :
PILOT KNOWN UNKNOWN FREE-STYLE OVERALL
Andre' Stockwell 71.94 64.98 63.3 68.23
Neville Wright 71.45 63.4 67.6 67.83
Brett Black 67.37 66.72 62.5 66.62
Gavin Walton 65.74 62.95 50.8 63.13
Morne' Brooks 64.55 62.66 0 57.34
Ian Edwards 53.3 53.66 50 53.12
Peter Labuschagne 44.38 50.35 44.2 46.75
Mike Hearn 39.2 51.4 0 40.12
The Free-Style was won by Neville Wright.
This was a very successful event and we look forward to a bigger and better event this year.
Thanks to RMAC for the use of their excellent facility, to the judges who gave up their time so we could have fun, to Richard Newton who designed the schedules, to the LSMAA committee for their input and finally to the competitors for making the event worth having.
I agree with Andre, most older kits do not have the space for battery packs and may cause the CG problem mentioned.
Alternative and better priced motors ie MSComposit Twister motors are available that have the same performance as AXI and/or better. Most of these bigger Twister motors have a very nice metal mount, keeping the motor open to all possible cooling, these mounts are perfect for the type of 3D airplanes. In cowl mounts for scale aircraft's are also available.
Check this site for Hanger 9 90 size Mustang electric conversion.
Newer packs are also available from Kokam ie 4S1P 3200 and 5S1P 3200 packs. Now you only have to charge one or maybe 2 packs at a time. Better voltage for better punch and with these packs in parallel the possibility for large scale are endless.
Sunday, January 02, 2005
I started the SAMAA web site in September 1997. That’s a long time ago in Internet Time. By December 2004 the site had grown to nearly 900 files.
Many people have said that it is hard to find things on the site. I can understand this. I’m the editor and I find it hard sometimes. The time has come to make it easier.
The old site was a bit of a jumble. I mixed notes the Association with news. I hope to separate these. The site will contain details of the Association. News will go into the BLOG.
I am finding the process of revamping the site quite difficult. The site pages are linked together in surprising ways. So at first I won’t remove anything. I’ll reconnect links from the Home Page. Lower down all the old links are still in place. You will find that you can get into the “old site” from many pages. In time I’ll remove all these old links.
- Control Line SIG
- Fun Fly SIG
- Gert Nieuwoudt's SAMAA Facebook page
- Large Scale Aerobatics SIG
- MGA SIG
- MHSA SIG
- Model Aerobatic Association SIG
- National Association of Scale Modelers SIG
- SA Indoor Electric Association
- SAMAA Diary of Events
- SAMAA membership admin site
- SAMAA web page
- SAMJA SIG
- SAMPRA SIG
- ► 2014 (33)
- ► 2013 (44)
- ► 2012 (57)
- ► 2011 (67)
- ► 2010 (79)
- ► 2009 (78)
- ► 2008 (102)
- ► 2007 (108)
- ► 2006 (90)
- Changes to SAMAA web site
- General Circular from Bob Skinner
- Andre Kilian on a DIY outrunner motor
- Savas Nicolaides on the 2004 Aerobatic masters
- Claude MacKrill on Murphy's Law
- 2004 Tip of Africa Fly In
- Tip of Africa Fly In Yak 54 with MVVS 59cc gas e...
- Tip of Africa Fly In -- Finley receiving his troph...
- 2004 LSMAA TOC report by Gavin Walton
- 2004 LSMAA TOC winners.
- Comment by BallisticRC
- New Site Layout
- ▼ January (12)